About the Planting of Noah (110-111)

But we, even after we have been instructed, make no progress in learning; but some persons, having a self-taught natural instinct, purify what is good from the evils which surround it, as Jacob did, he who was surnamed the practiser of virtue; for he "peeled the rods, leaving on the white bark, having stripped off all the green;" [*] in order that the dark and dusky vanity in the middle being taken away in every case, a white appearance might be displayed, which should be produced so as to be akin to it, not by diversified art but by nature;

in reference to which it is also commanded in the law which was established in cases of leprosy, that "the man who was not infected with any variation of colour, but who was white all over from the head to the extremity of his feet, should be pure." [*] In order that, according to the similitude of the body, those who have discarded the crafty, and unscrupulous, and ambiguous, and uncertain disposition of mind, may embrace the simple, uncoloured, unambiguous, plain complexion of truth;